Such unit bearing arrangements are known and serve the limitation of movements which are caused by the engine and which are transmitted via a support member to the bearing body of the arrangement, said bearing body optionally being configured in multiple parts, and the forces which occur are led off at the pivot points of the support member at the vehicle body. They are in particular especially used in automotive engineering in large volumes for the support of the transmission. Simple embodiments of such bearings substantially comprise an elastomer bearing body and a rigid bearing housing which surrounds and receives the bearing body. In this respect, on a use of the bearings in accordance with their intended purpose, the respective bearing bodies carry out movements relative to the bearing housing on operation of a vehicle equipped with them due to the loads which occur within the bearing housing. These relative movements of the bearing body have to be limited in this regard with respect to the respective enabled path in the different directions so that the bearings are equipped with abutments which are formed by the bearing housing on the basis of a corresponding shaping of the housing or which are formed, however, at least at the bearing housing by means of corresponding additional elements. The abutments can in this respect also form parts of a multi-part bearing body.
Abutments for the relative movements of the bearing body are required in the three main directions of load for the use in automotive engineering. These abutments limit the movement of the bearing body in the X direction, that is in the longitudinal direction of the vehicle or with respect to the direction of travel; in the Y direction, that is transversely to the longitudinal direction of the vehicle or with respect to the direction of travel; and in the Z direction, that is with respect to the vertical extent of the vehicle, in each case both with respect to the respective positive component and with respect to the corresponding negative component of the corresponding direction vector.
In this respect, the support members are pre-treated in total with the known unit bearings, with the pre-treatment comprising a degreasing washing and a roughening of the surface to increase the surface by a blasting process, for example by corundum blasting. The support members known from the prior art are subsequently coated at a region provided for this purpose by vulcanization with an elastomer material and are subsequently installed. The surface connected to the elastomer material by vulcanization in this process ultimately, however, only amounts to approximately 50% of the total surface. During the pre-treatment, parts of the respective support member have in this respect to be covered such that the surfaces not to be rubberized are free from adhesive.
The solid support members, frequently comprising an aluminum die casting, furthermore have to be preheated prior to the vulcanization, with work alternatively also being carried out with delayed injection in order subsequently to achieve a uniform wetting with the elastomer applied. The dimensions of the support members in this respect bring about a reduction of the number of possible cavities within the vulcanization tool.
It is therefore the object of the present invention to provide an elastomer bearing which reduces or even totally avoids the aforesaid disadvantages and can thus be manufactured faster and more favorably.
This object is achieved by a unit bearing of the initially named kind in which at least one common carrier element is arranged between the support member and the elastomer abutments of the bearing body and simultaneously spaces the support member from all elastomer abutments. The support member is therefore actually separated from the abutments by the at least one carrier element and the vulcanization can only take place at the at least one carrier element so that, conversely, the support member can be excluded from the vulcanization. This circumstance makes it possible to connect the elastomer abutments first permanently to the at least one carrier element and only then to connect the created assembly releasably to a section of the support member. The elastomer to be vulcanized to the support member can, for instance, first be applied to a carrier element in the form of a plastic carrier plate which is admittedly subsequently fixed to the support member, but is nevertheless releasably connected to it.
The initially described pre-treatment (washing and blasting) is now dispensed with by the described separation of the abutments from the support member and their application to a carrier element especially provided for this purpose. It furthermore has a time-saving effect that a preheating of the support member or a delayed injection can be dispensed with. In addition, an increased yield of support members provided with abutments can be achieved since a higher number of cavities, for example twice the number, is available in the vulcanization tool. In addition, a cost saving can also be based on the fact that a defective vulcanization, which can indeed occur, does not immediately have the result that the support member becomes a reject. The releasable connection between the carrier element and the carrier plate furthermore has a positive effect in the development process, and here in particular in the coordination phase, since carrier elements having a different elastomer material, which varies in Shore hardness, for example, can be replaced in a simple manner.
Further advantageous embodiments of the unit bearing result from the dependent claims.
A durable connection between the carrier element and the support member is achieved in an advantageous embodiment in that the carrier element forms at least one shape fit with at least one region of the support member in the position of use and on its interlocking by one or more regions of the carrier element with those of the support member, the release movement of the two connection partners is blocked in at least one direction.
In this respect, in an advantageous embodiment, the carrier element can be provided with one projection or with a plurality of projections which engages/engage in cut-outs located at the support member and/or vice versa. The converse means the formation of the projection or projections at the support member.
Expediently, in further developments of the unit bearing, the projections have a geometrical shape in cross-section which can be simply implemented, which provides the required surfaces for forming the shape fit and which does not make any undercuts necessary at a shaping tool for producing carrier elements. Equally, the undercuts can also be dispensed with in the tools for manufacturing support members which consist of an aluminum die casting, for example. Such geometrical shapes can be cruciform or triangular in cross-section, for example.
In a preferred further development, the projections can vary their cross-sections over their extents and can in particular taper in the projecting direction, so that they, for example, extend conically in the direction of the associated tool chamfer of the manufacturing tool, which facilitates the subsequent mold removal. A triangular cross-section of the projections which tapers in the projecting direction can thus engage into corresponding cut-outs. A kind of honeycomb structure, in which the multiple, planar contact of the surfaces of the carrier element at those of the support member ensures a better force distribution, can be formed with a plurality of such projections which form a quadrangle, for instance, in cross-section adjacent to one another. This honeycomb structure or also another suitable structure can also form a kind of thread-in aid in the arrangement of the carrier element at the support member.
In another embodiment of the unit bearing advantageously counteracting the release movement of the carrier element from the support member, the carrier element can contact at least two oppositely disposed side surfaces of the support member in a planar manner in the position of use and can be preloaded toward them. The side surfaces can hereby, on the one hand, counteract a movement in parallel with their perpendicular; however, due to the preload of the contact surfaces of the carrier element, a force fit can also be formed which inhibits a movement in parallel with the side surface of the support member.
An embodiment of the unit bearing can comprise at least one section of the support member having a substantially quadrangular contour and the carrier element engaging over this section at three sides and at corner regions which bound an uncovered side such that, with a carrier element arranged at the support member, a kind of transport securing device is also formed for the former by the engaging over in the corner regions, said transport securing device holding the carrier element captive at the support member by the abutments.
The support member can generally be provided over its longitudinal extent and over its cross-sectional extent with a cross-section variation which can respectively represents surfaces for forming a shape fit.
In another embodiment of the unit bearing, the carrier element has a contour which corresponds to the covered section of the support member or which differs therefrom such that a higher coordination flexibility and variant flexibility can be produced by a replacement of the respective carrier element which can in turn also have an effect on the contours of the elastomer abutments which can in turn then be designed more flexibly. Depending on the design of the support member, the possibility may also result of replacing a part of its body volume with the carrier element so that then a weight reduction also advantageously accompanies an arrangement of the carrier element in the position of use.
In a further development of the unit bearing, the elastomer abutments expediently form a common abutment body which completely encompasses the carrier element in which it is connected to the support member in the position of use. In this respect, the respective margins of abutment bodies and carrier element can terminate flush at the support member. The abutment body itself can in this respect be considered a part of the bearing body at which the support body is supported against the bearing housing.
In another embodiment of the unit bearing, the carrier element can be formed from a thermoplastic. This embodiment is advantageous, in particular with regard to a grease-free production of the carrier element and to a direct application of adhesive. The carrier element can be manufactured simply and inexpensively in this manner by means of corresponding tools in an injection molding process. The respective plastic can preferably be formed from a polyamide which forms a construction material very suitable for the carrier element due to its properties of high strength and toughness and due to its chemical resistance. Other materials such as polysulfides, polysulfones, polyimides or polyketones are also conceivable, however.
The problem mentioned above is also solved by a method of manufacturing a unit bearing, in particular a unit bearing as has already been described above, that is having an elastomer bearing body which is received in a rigid bearing housing provided with an opening at at least one side, wherein at least one support member engages through the at least one opening and is supported against the bearing housing at the bearing body, and wherein relative movements of the bearing body with respect to the bearing housing caused by loading of the support member along three mutually orthogonal directions of extent of the bearing body at both sides of a position of rest of the respective relative movement can be limited by elastomer abutments arranged between the bearing housing and the support member. The respective method is characterized in that the elastomer abutments are first permanently connected to a carrier element and the created assembly is subsequently releasably connected to a section of the support member. The support function of the support member for the unit is hereby decoupled from the carrier function for the elastomer abutments of one or more abutment bodies which can optionally also be associated with the bearing body of the unit bearing.
In an advantageous variant of the method, an abutment body formed from the elastomer abutments can be attached directly to the carrier element while applying an adhesive in order subsequently to be vulcanized. The vulcanization of the abutment body therefore takes place without the support member. It is also conceivable to vulcanize a plurality of abutments or abutment bodies to the carrier element in the same process.